Category Archives: Lawns & Grass

I grew up in an apartment in Manhattan, so anything green seemed natural to me. It’s only much more recently that I’ve come to see lawns as man-made objects imposed on the environment—often an unforgiving and unreceptive environment.

Then Eric Vinge of Planet Natural asked me to write an article on organic lawn care. Writing that article (A Home-Owner’s Guide to Organic Lawn Care: Maintaining a Chemical-Free Lawn) was my education in lawn-care pesticides and other chemicals, and it was quite a class. Obviously, I started with a strong bias towards the organic point of view. But I have a strong skeptical streak, and I decided to trace every claim about rising cancer rates and endocrine disruption, about tracked-in chemicals, volatile organic compounds (VOCs) and the rest to either a university or a government study.

You know what I found? It was all true. All those claims about contaminated well-water and streams, the danger of childhood exposure, reproductive disorders—they’re all true.

I’ve got a question for all of you: Can an organic garden service that farms out toxic weed control still call itself organic? Has it sacrificed its integrity, its very soul, or is such language uselessly hyperbolic in such a case?

Let me explain how the question arose. Given the paucity of garden-related businesses that had booths at Bozeman’s poorly-named home and garden show (subject of one of my more acerbic posts), I had time for conversations with the folks staffing all three. Indeed, I swooped down on the two booths for organic gardening services, partly out of sheer delight that they existed, but in part to ask a highly pertinent question: How did they handle bindweed on a residential property?

Got an e-mail recently from a very interesting fellow who’s just written a book about the chemistry and ecology of synthetic nitrogen fertilizers, and if you haven’t had your fix of ecological chills recently, keep reading. The e-mail arrived in the midst of the Sock Wars, so I scrutinized it with more than ordinary vigilance, as if it might blow up in my face (revealing another face under a large hat, laughing madly), or as if the virus it harbored might bloom suddenly into sock-tossing flowers.

Having eventually decided (using a fool-proof method of one part deduction and eight parts pure guess-work) that the e-mail was legit, I followed the link provided and found myself reading a long and compelling passage about the unintended and dangerous consequences of nitrogen fixation, the basis for nitrogen fertilizers.

The fixation process, which takes nitrogen from the atmosphere (where it makes up 70% of the air we breathe) and incorporates it into compounds, has doubled the amount of nitrogen in and on the earth. When it’s applied to land as fertilizer, some of it is released as gas – and while some of that gas is the same harmless, inert N2 that we breathe all the time, some is now bonded with oxygen, forming the green-house gas nitrous oxide.

Having gone on at some length a while ago (twice!) about how wood ashes aren’t going to cause lead or mercury or cadmium poisoning if you use them in your garden, I am now prepared to tout them as the nearly-perfect lawn fertilizer. Since it seems that I’ve adopted this poor, misunderstood amendment as my own, I might as well do it thoroughly.

Grass needs calcium, which might be considered a non-renewable resource in a lawn: once the roots have used it up, it’s gone. So additions are necessary. The most common materials for such additions are gypsum, which contains about 22% calcium, and lime, at about 30%. The calcium content of ashes varies widely depending on type of wood, but even softwoods will produce ashes containing about 15% calcium, and hardwood ash may be as high as 50%.

A couple of things make ash a superior amendment, especially for lawns. For one thing, both gypsum and lime are quite insoluble. The term “immobile” seems an excellent metaphor for how they behave when applied to grass, but it’s also the technical term for a compound that doesn’t dissolve easily and therefore doesn’t move with water into and through soil. As a result, it is hard to get lime and gypsum into a plant: unless they’re snugged right up against the roots, they might as well be on Mars, for all the good they’ll do.

A couple of years ago I read that sawdust was the last thing you wanted to sprinkle on your lawn (unless you liked that sickly yellow color), but I’d completely forgotten why. This did not keep me up at night until recently, when I was working on the soil amendments part of my endless organic lawn care article (I’m up to page 112, and counting), and wanted to say something intelligent about sawdust as an amendment.*